We proposed to determine the nature of the ordered structures in which glycosaminoglycans participate in oriented and crystalline fibers and films. The main technique involved is a form of X-ray diffraction analysis in which the low resolution data is supplemented by stereochemical data. The information sought includes the conformations of the (usually helical) polysaccharide chains, their packing interactions, the positions of water molecules and countercations. Attempts will be made to rationalize the physico-chemical and biological properties of these molecules using the detailed models that emerge from the X-ray work.